It didn’t help that Keselowski’s engine sputtered when the voltage in his battery dropped dangerously low.

But Keselowski built a big enough lead after a restart on Lap 168 of 200 to ward off Busch’s charge in the closing stages of the race.

Keselowski’s first win of the season, his first at LVMS and the 28th of his career left Busch, a Las Vegas native, frustrated in his 11th futile attempt to win a Nationwide Series race on home turf. Busch was runner-up for the second straight year and third time overall.

“Kyle’s one of the best in the business, and he deserves a win here, and he’s been real close, just like we have,” said Keselowski, who was leading on the final lap in 2011 before a blown tire knocked him back to third.

“These races aren’t getting any easier to win. I drove as hard as I could every lap, knowing that Kyle was coming there, especially at the end. We were having some troubles with the engine there, and I knew it was just a matter of time before he caught me. I was just trying to get through as much traffic as I could and extend that time and was counting down the laps. It felt good that everything worked out at the end.”

Busch dropped to the rear for the start of the race, because his crew made an unapproved adjustment to the No. 54 Toyota after impound, replacing a frayed alternator belt. By Lap 12, however, Busch had cracked the top 10 and continued to advance through a 56-lap green-flag run to start the race.

When NASCAR slowed the field with a debris caution, Busch was third, having gained two positions during an exchange of pit stops under green.

But Keselowski was dominant during the middle third of the race, and after a restart on Lap 75 — a result of the second caution for Dylan Kwasniewski’s brush with the Turn 3 wall on Lap 70 — he drove away from Busch, who was running second.

A second cycle of green-flag stops put Busch in the lead on Lap 131. By then, there were seven cars on the lead lap.

Busch had a half-second lead when NASCAR called the third caution on Lap 148 because of debris in Turn 2. During pit stops under yellow, Keselowski overshot his pit stall, dropped three positions and restarted fifth on Lap 152, with Busch leading the field to green.

Seven laps later, after an intense battle for the lead, Kenseth spun in Turn 4 trying to keep pace with Busch but adroitly kept the No. 20 Toyota off the wall and saved the car from damage.

Keselowski rocketed into the lead moments after the subsequent restart on Lap 162 and held it the rest of the way. Busch picked the outside lane for that restart and immediately dropped positions to Keselowski and Elliott but didn’t consider that choice a decisive factor.

“I stepped on the gas, and it felt like I was holding a parachute, the way those guys went by me,” Busch said. “I was third before I even got to Turn 1. Junior was pushing me there for a little bit. I don’t know happened, if he fell off me or what, but… it just wouldn’t go.”